1. Field of the Invention
The present invention relates to a digital camera for recording a captured image as digital data, to a method of adding a function to the digital camera, and to a system for detecting falsification of the image data recorded in the digital camera.
The present application is based on Japanese Patent Application No. Hei. 11-251660, which is incorporated herein by reference.
2. Description of the Related Art
In a conventionally-used camera, light which enters a camera at the time of a photographing operation is radiated onto a film, to thereby cause a chemical reaction and record an image on the film. The film is then developed and printed onto photographic paper. Reaction of silver chloride is commonly used as a chemical reaction for photographing. A photograph shot by such a camera is called a silver salt photograph.
Meanwhile, a digital camera is currently coming into widespread use. In the digital camera, a photosensor such as a charge-coupled device converts light into an electrical signal, and the electrical signal is further converted into a digital signal. The digital signal is recorded in a recording medium such as flash memory or the like. Use of a digital camera enables a user to personally and easily preserve or process an image in various manners through use of a processing device such as a personal computer. Further, if an image is output through use of a printer, a photograph can be printed without development of a film. In association with an improvement in print quality of a printer, it has become possible to print a high quality photograph which is hard to distinguish from a silver salt photograph.
As mentioned above, an image photographed by a digital camera can be easily processed through use of a personal computer or a like device. Further, the image photographed by a digital camera can be processed without involvement of a vestige more easily than a silver salt photograph. For this reason, in the case of photographic evidence utilized in the field of non-life insurance, if a photograph shot by a digital camera is used as important photographic evidence, the photograph may be susceptible to abuse.